Sea level rise is a growing threat to many coastal communities worldwide.

PHOTO: GEORGE STEINMETZ/NATIONAL GEOGRAPHIC CREATIVE

One of the most important consequences of global warming is sea level rise, and better determining how fast it is occurring is vital for understanding the climate system and formulating adaptive policy. Dieng et al. used 26 separate data sets to determine global mean sea level (GMSL) since October 1992, when satellite altimetry measurements of sea levels began. They find that although the average rate of GMSL rise between January 1993 and December 2015 was close to 3.0 mm/year, the rate was 0.8 mm/year higher during the period 2004–2015 than it was during 1993–2004. Most of that increase was due to mass loss from the Greenland Ice Sheet, but all other components of the budget contributed as well.